Air Conditioner Nuclear Power Plant Filters 20x20x4
Most countries use traditional baffle filters in nuclear power plants. The filter material is glass fiber filter paper, the baffle is 0.038mm aluminum foil, the outer frame is carbon steel or stainless steel, the adhesive between the filter paper and the outer frame is silicone, PVC or other heat-resistant materials, and the windward and leeward sides of the filter have metal protective nets. Many of the performances of Air Conditioner Nuclear Power Plant Filters 20x20x4 are "redundant performance" in normal times, and those performances are considered for reliability in accidents.
France is the originator of baffle-free filters. The French successfully replaced traditional baffle filters with baffle-free filters in nuclear power plants. South Korea and China imported French nuclear power plants and realized the localization of filter production. Except for these three countries, no one dared to use baffle-free high-efficiency filters in key parts of nuclear power plants.
The high-efficiency filters used in China's early nuclear reactors were similar to those in the United States. Later, China introduced nuclear power plants in France, Canada, and Russia. China's nuclear-grade filters are not many in number, but there are many styles.
----------------------------High-efficiency filters----------------------------
In order to prevent radioactive dust from spilling into the atmosphere, the exhaust system of nuclear power plants requires a large number of high-efficiency filters. The US standard stipulates that the efficiency of this high-efficiency filter is: 99.97% for 0.3mm DOP particles. Most countries have copied the US standard, and some countries have stipulated their own test methods, but the 20x20x4 air filter performance is equivalent to that measured by the US method.
----------------------------Activated carbon filter----------------------------
Methyl iodide and iodine are fission products of the radioactive element uranium. They are radioactive gases unique to the nuclear industry. In order to remove methyl iodine and iodine vapor from the air, nuclear power plants use a large number of activated carbon filters. Activated carbon materials for this purpose must undergo special chemical impregnation treatment to improve the adsorption capacity of methyl iodine and iodine. Traditionally, people call activated carbon materials used in the nuclear industry "nuclear grade carbon" and activated carbon filters "iodine adsorbers".
Compared with ordinary activated carbon filters, filters used in nuclear power plants have thick carbon layers, high adsorption efficiency, and high temperature and seismic requirements.
Since adsorption is an exothermic process, excessively high temperatures may ignite activated carbon, so there are strict temperature requirements for iodine adsorbers. The concentration of methyl iodide and iodine in nuclear fuel processing plants is very high. At this time, activated carbon can no longer be used. Instead, other non-flammable porous adsorption materials are used to make iodine adsorbers.
----------------------------Ventilation filters----------------------------
According to consumption, the largest amount of filters used in nuclear power plants is general ventilation filters, which are used in reactors, auxiliary plants, offices and service areas.
There are various forms of ventilation filters used in nuclear power plants. It should not be so particular, but the specific specifications of the filters are determined at the beginning of construction, and the filter company must supply them according to the original specifications. Unless there is an accident, the owner and the supplier dare not easily change the raw materials, manufacturing process, test methods and supply channels.
Safety first
The principle and structure of filters used in the nuclear industry are not much different from those used in other industries. Nuclear industry filters do not seek high-tech, market economy, or bargaining.
Safety first, reliability first.
Compared with filters used in other industries, filters used in the nuclear industry must undergo more testing items and more certifications. Those inspections and certifications are often done by specialized agencies related to the nuclear industry controlled by the government. In addition, the 20x20x4 merv 11 supplier must have reliable qualifications and credibility, receive more or less government support, and have considerable performance and corresponding technical strength.
----------------------------PCR laboratory anti-pollution measures and emergency treatment methods----------------------------
PCR experiments are based on microscopic sample experiments at the nucleic acid level, and these microscopic samples are very sensitive to experimental environments such as temperature and pH. While trying to maintain the sample storage environment, nucleic acid sample contamination has also become an inevitable topic. "Easy to check but not easy to detect", contamination comes quietly. Today, the editor will briefly introduce the main sources of contamination in PCR laboratories, how to avoid and reduce the possibility of contamination in experiments, and emergency treatment plans for experimental contamination.
----------------------------Sources of contamination in PCR laboratories----------------------------
Cross-contamination between samples:
The container for collecting samples is contaminated or the sample is not sealed tightly and overflows; forget to change the gun tip when pipetting different samples or do not use the gun tip with 20x20x4 air filter merv 11 element; experimental instruments and consumables such as pipettes are not disinfected and sterilized in time; different samples are opened at the same time or the samples are violently shaken and repeatedly blown and sucked, resulting in the formation and diffusion of aerosols, and cross-contamination.
Experimental reagent contamination:
During the preparation of reagents, the addition of nucleic acid templates leads to contamination.
Amplification product contamination:
A large number of copies of the product leak or the PCR reaction tube is accidentally opened after amplification.
Cloning plasmid contamination:
The cloning plasmid as a positive quality control product overflows.
Anti-pollution methods for PCR laboratories
----------------------------Reasonable laboratory zoning----------------------------
The experimental supplies in the reagent preparation area, sample preparation area and amplification area, including pipettes and other instruments, should be dedicated, and the air and items flow in the following order: reagent preparation area, sample preparation area, amplification area, product analysis area, and cannot be reversed.
Clean experimental supplies:
Laboratory self-prepared reagents (deionized water, buffer, etc.) and all instruments used should be autoclaved or UV sterilized before use. Experimental consumables such as gun tips and reaction tubes should be used once.
----------------------------Correct experimental operation----------------------------
The experiment should be carried out in an ultra-clean workbench, where a PCR-specific microcentrifuge, pipettes of various ranges and other necessary items should be placed.
During the experiment, choose the most suitable size of gloves and change them in time. When entering and leaving different experimental areas or performing template operations, you should change your lab coat, mask, hat and gloves to avoid cross-contamination between different experimental areas.
Before opening the reaction tube containing PCR reagents, centrifuge it instantaneously to remove the liquid on the tube wall and tube cover to the bottom of the tube to reduce the risk of contaminating gloves or samplers; open the reaction tube carefully to prevent the liquid in the tube from splashing or forming aerosols to cause contamination.
The operation of adding reagents and templates should be carried out strictly in accordance with the specifications, abide by the principle of "slow suction and fast injection", try to complete it in one time, and avoid multiple suctions to avoid cross contamination caused by aerosols.
It is recommended to package PCR reagents in small amounts to reduce repeated freezing and thawing and repeated sampling times; when reacting multiple samples with PCR, first prepare the reaction mixture and dispense it into the reaction tube, and finally add the sample nucleic acid. Do not open the cover at the same time, try to ensure that one person and one tube are used, and achieve completely closed tube operation.
The experimental reagents should be stored separately from the samples and PCR products, and should not be placed in the same place.
After the PCR amplification experiment is completed, take out the reaction tube in time, wrap the product reaction tube with disposable gloves and discard it, and ensure that the tube cover is tightly closed.
----------------------------Standardized experimental design----------------------------
Follow the relevant regulations of laboratory internal quality control, set up positive control, negative control and blank control in the experiment, and control the whole process of the experiment to verify the reliability of the PCR reaction and help judge the credibility of the amplification system.
Emergency treatment method for contamination in PCR laboratory
If the nucleic acid sample overflows:
Immediately cover it with cloth or paper towel, pour 10% hypochlorous acid disinfectant from the outside to the center, remove the contaminated items after about 30 minutes, wipe with hypochlorous acid disinfectant, spray with 75% alcohol, and move the UV car to irradiate for 1 hour.
----------------------------Other unknown pollution----------------------------
1. Suspend all experimental operations;
2. Clean all items in the laboratory and find the source of pollution;
3. Increase ventilation in the laboratory;
4. Disinfect all surfaces in the laboratory (tables, floors and walls);
5. Spray 75% alcohol in the air;
6. Turn on the ultraviolet disinfection device and extend the ultraviolet irradiation time (more than 4 hours);
7. The above measures are carried out daily until the pollution is eliminated; use new reagents and equipment confirmed to be pollution-free to perform reagent blank tests for the original contaminated items. Routine testing can only be carried out after three consecutive negative results.
Keywords: air conditioner filters 20 x 20 x 4 | Air Conditioner Nuclear Power Plant Filters 20x20x4 | best 20x20x4 air filter | 20x20x4 air filter near me | air conditioner filters 20x20x4 | 20 x 20 x4 air filter
